From: Joanne Koong Date: Tue, 30 Nov 2021 03:06:20 +0000 (-0800) Subject: selftests/bpf: Add bpf_loop test X-Git-Tag: v6.1-rc5~2306^2~228^2~24^2~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4e5070b64b375a9c1f570893cfceeba108382bef;p=platform%2Fkernel%2Flinux-starfive.git selftests/bpf: Add bpf_loop test Add test for bpf_loop testing a variety of cases: various nr_loops, null callback ctx, invalid flags, nested callbacks. Signed-off-by: Joanne Koong Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211130030622.4131246-3-joannekoong@fb.com --- diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_loop.c b/tools/testing/selftests/bpf/prog_tests/bpf_loop.c new file mode 100644 index 0000000..380d7a2 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/bpf_loop.c @@ -0,0 +1,145 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ + +#include +#include +#include "bpf_loop.skel.h" + +static void check_nr_loops(struct bpf_loop *skel) +{ + struct bpf_link *link; + + link = bpf_program__attach(skel->progs.test_prog); + if (!ASSERT_OK_PTR(link, "link")) + return; + + /* test 0 loops */ + skel->bss->nr_loops = 0; + + usleep(1); + + ASSERT_EQ(skel->bss->nr_loops_returned, skel->bss->nr_loops, + "0 loops"); + + /* test 500 loops */ + skel->bss->nr_loops = 500; + + usleep(1); + + ASSERT_EQ(skel->bss->nr_loops_returned, skel->bss->nr_loops, + "500 loops"); + ASSERT_EQ(skel->bss->g_output, (500 * 499) / 2, "g_output"); + + /* test exceeding the max limit */ + skel->bss->nr_loops = -1; + + usleep(1); + + ASSERT_EQ(skel->bss->err, -E2BIG, "over max limit"); + + bpf_link__destroy(link); +} + +static void check_callback_fn_stop(struct bpf_loop *skel) +{ + struct bpf_link *link; + + link = bpf_program__attach(skel->progs.test_prog); + if (!ASSERT_OK_PTR(link, "link")) + return; + + /* testing that loop is stopped when callback_fn returns 1 */ + skel->bss->nr_loops = 400; + skel->data->stop_index = 50; + + usleep(1); + + ASSERT_EQ(skel->bss->nr_loops_returned, skel->data->stop_index + 1, + "nr_loops_returned"); + ASSERT_EQ(skel->bss->g_output, (50 * 49) / 2, + "g_output"); + + bpf_link__destroy(link); +} + +static void check_null_callback_ctx(struct bpf_loop *skel) +{ + struct bpf_link *link; + + /* check that user is able to pass in a null callback_ctx */ + link = bpf_program__attach(skel->progs.prog_null_ctx); + if (!ASSERT_OK_PTR(link, "link")) + return; + + skel->bss->nr_loops = 10; + + usleep(1); + + ASSERT_EQ(skel->bss->nr_loops_returned, skel->bss->nr_loops, + "nr_loops_returned"); + + bpf_link__destroy(link); +} + +static void check_invalid_flags(struct bpf_loop *skel) +{ + struct bpf_link *link; + + /* check that passing in non-zero flags returns -EINVAL */ + link = bpf_program__attach(skel->progs.prog_invalid_flags); + if (!ASSERT_OK_PTR(link, "link")) + return; + + usleep(1); + + ASSERT_EQ(skel->bss->err, -EINVAL, "err"); + + bpf_link__destroy(link); +} + +static void check_nested_calls(struct bpf_loop *skel) +{ + __u32 nr_loops = 100, nested_callback_nr_loops = 4; + struct bpf_link *link; + + /* check that nested calls are supported */ + link = bpf_program__attach(skel->progs.prog_nested_calls); + if (!ASSERT_OK_PTR(link, "link")) + return; + + skel->bss->nr_loops = nr_loops; + skel->bss->nested_callback_nr_loops = nested_callback_nr_loops; + + usleep(1); + + ASSERT_EQ(skel->bss->nr_loops_returned, nr_loops * nested_callback_nr_loops + * nested_callback_nr_loops, "nr_loops_returned"); + ASSERT_EQ(skel->bss->g_output, (4 * 3) / 2 * nested_callback_nr_loops + * nr_loops, "g_output"); + + bpf_link__destroy(link); +} + +void test_bpf_loop(void) +{ + struct bpf_loop *skel; + + skel = bpf_loop__open_and_load(); + if (!ASSERT_OK_PTR(skel, "bpf_loop__open_and_load")) + return; + + skel->bss->pid = getpid(); + + if (test__start_subtest("check_nr_loops")) + check_nr_loops(skel); + if (test__start_subtest("check_callback_fn_stop")) + check_callback_fn_stop(skel); + if (test__start_subtest("check_null_callback_ctx")) + check_null_callback_ctx(skel); + if (test__start_subtest("check_invalid_flags")) + check_invalid_flags(skel); + if (test__start_subtest("check_nested_calls")) + check_nested_calls(skel); + + bpf_loop__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/bpf_loop.c b/tools/testing/selftests/bpf/progs/bpf_loop.c new file mode 100644 index 0000000..12349e4 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_loop.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ + +#include "vmlinux.h" +#include + +char _license[] SEC("license") = "GPL"; + +struct callback_ctx { + int output; +}; + +/* These should be set by the user program */ +u32 nested_callback_nr_loops; +u32 stop_index = -1; +u32 nr_loops; +int pid; + +/* Making these global variables so that the userspace program + * can verify the output through the skeleton + */ +int nr_loops_returned; +int g_output; +int err; + +static int callback(__u32 index, void *data) +{ + struct callback_ctx *ctx = data; + + if (index >= stop_index) + return 1; + + ctx->output += index; + + return 0; +} + +static int empty_callback(__u32 index, void *data) +{ + return 0; +} + +static int nested_callback2(__u32 index, void *data) +{ + nr_loops_returned += bpf_loop(nested_callback_nr_loops, callback, data, 0); + + return 0; +} + +static int nested_callback1(__u32 index, void *data) +{ + bpf_loop(nested_callback_nr_loops, nested_callback2, data, 0); + return 0; +} + +SEC("fentry/__x64_sys_nanosleep") +int test_prog(void *ctx) +{ + struct callback_ctx data = {}; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + nr_loops_returned = bpf_loop(nr_loops, callback, &data, 0); + + if (nr_loops_returned < 0) + err = nr_loops_returned; + else + g_output = data.output; + + return 0; +} + +SEC("fentry/__x64_sys_nanosleep") +int prog_null_ctx(void *ctx) +{ + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + nr_loops_returned = bpf_loop(nr_loops, empty_callback, NULL, 0); + + return 0; +} + +SEC("fentry/__x64_sys_nanosleep") +int prog_invalid_flags(void *ctx) +{ + struct callback_ctx data = {}; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + err = bpf_loop(nr_loops, callback, &data, 1); + + return 0; +} + +SEC("fentry/__x64_sys_nanosleep") +int prog_nested_calls(void *ctx) +{ + struct callback_ctx data = {}; + + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + nr_loops_returned = 0; + bpf_loop(nr_loops, nested_callback1, &data, 0); + + g_output = data.output; + + return 0; +}